[3I10-12] Evaporation and Dryness of Radioactive Solution 2

[3I12] Study on ruthenium volatilization during evaporation and dryness of nitrate solution

Effect of coexisting nitrates on formation of volatile ruthenium tetroxide

*Tetsuya Kato¹, Tsuyoshi Usami¹, Takeshi Tsukada¹ (1. CRIEPI)

Keywords:high-level liquid waste, ruthenium, volatilization, cooling malfunction accident

In a cooling malfunction accident of a high-level liquid waste (HLLW) tank, part of radioactive ruthenium (Ru) is potentially released to the environment as volatile RuO₄. In this study, mixed nitrates of Ru and main element in HLLW such as cerium, neodymium, or zirconium was heated up to 723 K and RuO₄ evolved during the dryness and denitration were measured by means of the mass spectrometer to discuss effect of the coexisting nitrates on RuO₄ formation efficiency.